Solar Collector

ABSTRACT

A solar concentrator for heating a fluid has an extended solar reflector with a plurality of reflective concave steps, each step having an apex offset vertically and horizontally from a reflector apex of the reflector. A conduit through which the fluid flows is positioned along a common focal line of each step, preferably on an underside of the conduit. A framework is fixed with the reflector and conduit and is adapted for holding the reflector and conduit in a fixed mutual relationship. In use, with the reflector positioned towards the sun, rays from the sun reflect from each step to concentrate along the focal line on the conduit to heat the fluid.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT

Not Applicable.

FIELD OF THE INVENTION

This invention relates to solar collectors, and more particularly to an improved solar collector design.

DISCUSSION OF RELATED ART

Solar collectors for heating fluid in a pipe are known in the prior art. Typically such collectors have a parabolic shape for focusing, in theory, the rays of the sun onto a common focal line along the fluid pipe. It is difficult to create a parabolic reflector so accurate as to create a clean, well-focused focus line on the conduit, which results in heating inefficiencies.

Therefore, there is a need for a device that more accurately reflects sunlight onto a water pipe in a solar collector. Such a needed device would be relatively easy to manufacture, and would result in an increased heating efficiency. The present invention accomplishes these objectives.

SUMMARY OF THE INVENTION

The present device is a solar concentrator for heating a fluid, such as water. An extended solar reflector has a plurality of reflective concave steps, each step having an apex offset vertically and horizontally from a reflector apex of the reflector. In one embodiment, the apex of each step is offset vertically and horizontally from the reflector apex in a substantially circular pattern. The apex of a bottom-most step is preferably collinear with the reflector apex. Preferably each concave step has a common curvature, such as a circular curvature.

A conduit through which the fluid flows is positioned along a common focal line of each step. Preferably the focal line is on an underside of the conduit. A framework is fixed with the reflector and conduit and is adapted for holding the reflector and conduit in a fixed mutual relationship. In one embodiment of the invention, the framework is adapted to be fixed with a sun tracking mechanism, as is known in the art, whereby as the sun moves across the sky during the day the sun tracking mechanism consistently points the concentrator theretowards.

In use, with the reflector positioned towards the sun, rays from the sun reflect from each step to concentrate along the focal line on the conduit to heat the fluid. In the embodiment with a sun tracking mechanism, the reflector follows the sun across the sky such that the conduit is always at the focal line created by each step when the rays of the sun strike the step and reflect onto the conduit.

The present invention is a device that more accurately reflects sunlight onto a water pipe in a solar collector. The present invention is relatively easy to manufacture, and results in increased heating efficiencies over conventional parabolic reflectors. Prior art collectors typically demonstrate heating efficiencies on the order of 45%-50%, while the present device demonstrates heating efficiencies of between 86% and 97%. Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the invention;

FIG. 2 is a diagram of the invention in use collecting solar energy; and

FIG. 3 is an enlarged, partial front elevational view of the invention, taken along lines 3-3 of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Illustrative embodiments of the invention are described below. The following explanation provides specific details for a thorough understanding of and enabling description for these embodiments. One skilled in the art will understand that the invention may be practiced without such details. In other instances, well-known structures and functions have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” Words using the singular or plural number also include the plural or singular number respectively. Additionally, the words “herein,” “above,” “below” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. When the claims use the word “or” in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list and any combination of the items in the list.

FIGS. 1-3 illustrate a solar concentrator 10 for heating a fluid 20, such as water or other suitable heat-exchange fluid. An extended solar reflector 30 has a plurality of reflective concave steps 40, each step 40 having an apex 45 offset vertically and horizontally from a reflector apex 35 of the reflector 30. In one embodiment, the apex 45 of each step 40 is offset vertically and horizontally from the reflector apex 35 in a substantially circular pattern 51, resulting in a segmented radial configuration as shown in FIG. 2.

The apex 45 of a bottom-most step 41 is preferably collinear with the reflector apex 35. Preferably each concave step 40 has a common curvature (FIG. 3), such as a circular curvature. In one embodiment, the plurality of steps 40 of the reflector 30 on either side of the apex 35 is between one and five, such as three. Each reflective step 40 is preferably made with a reflective surface, such as a polished metal material.

A conduit 70 through which the fluid 20 flows is positioned along a common focal line 60 of each step 40 (FIG. 2). Preferably the focal line 60 is on an underside 71 of the conduit 70. Preferably the conduit 70 is made from a metal material, such as copper, that is able to transfer heat relatively easily from the focal line 60 to the fluid 20. Further, the conduit 70 is made from a material that is capable of withstanding the intense heat generated at the focal line 60 without melting or deforming.

A framework 80 is fixed with the reflector 30 and conduit 70 and is adapted for holding the reflector 30 and conduit 70 in a fixed mutual relationship. In one embodiment of the invention, the framework 80 is adapted to be fixed with a sun tracking mechanism (not shown), whereby as the sun moves across the sky during the day the sun tracking mechanism consistently points the concentrator 10 theretowards. The framework 80 is preferably made from a rigid, durable material that is strong enough to withstand the outdoor elements and that does not significantly expand or contract with daily temperature fluctuations.

In use, with the reflector 30 positioned towards the sun, rays 15 from the sun reflect from each step 40 to concentrate along the focal line 60 on the conduit 70 to heat the fluid 20. In the embodiment with a sun tracking mechanism, the reflector 30 follows the sun across the sky such that the conduit 70 is always at the focal line 60 created by each step 40 when the rays 15 of the sun strike the step 40 and reflect onto the conduit 70.

While a particular form of the invention has been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention. For example, a different number of steps may be included from that shown in the figures. Accordingly, it is not intended that the invention be limited, except as by the appended claims.

Particular terminology used when describing certain features or aspects of the invention should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the invention with which that terminology is associated. In general, the terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification, unless the above Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the invention encompasses not only the disclosed embodiments, but also all equivalent ways of practicing or implementing the invention.

The above detailed description of the embodiments of the invention is not intended to be exhaustive or to limit the invention to the precise form disclosed above or to the particular field of usage mentioned in this disclosure. While specific embodiments of, and examples for, the invention are described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. Also, the teachings of the invention provided herein can be applied to other systems, not necessarily the system described above. The elements and acts of the various embodiments described above can be combined to provide further embodiments.

All of the above patents and applications and other references, including any that may be listed in accompanying filing papers, are incorporated herein by reference. Aspects of the invention can be modified, if necessary, to employ the systems, functions, and concepts of the various references described above to provide yet further embodiments of the invention.

Changes can be made to the invention in light of the above “Detailed Description.” While the above description details certain embodiments of the invention and describes the best mode contemplated, no matter how detailed the above appears in text, the invention can be practiced in many ways. Therefore, implementation details may vary considerably while still being encompassed by the invention disclosed herein. As noted above, particular terminology used when describing certain features or aspects of the invention should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the invention with which that terminology is associated.

While certain aspects of the invention are presented below in certain claim forms, the inventor contemplates the various aspects of the invention in any number of claim forms. Accordingly, the inventor reserves the right to add additional claims after filing the application to pursue such additional claim forms for other aspects of the invention. 

1. A solar concentrator for heating a fluid, comprising: an extended solar reflector having a plurality of reflective concave steps, each step having an apex offset vertically and horizontally from a reflector apex, a bottommost step having an apex that is collinear with the reflector apex, each reflective step having a common focal line; a conduit through which the fluid flows, the conduit positioned along the focal line of each step; a framework fixed with the reflector and conduit and adapted for holding the reflector and conduit in a fixed mutual relationship; whereby with the reflector positioned towards the sun, rays from the sun reflect from each step to concentrate along the focal line on the conduit to heat the fluid.
 2. The solar concentrator of claim 1 wherein the plurality of steps of the reflector on either side of the apex is between one and five.
 3. The solar concentrator of claim 1 wherein the plurality of steps of the reflector on either side of the apex is exactly three.
 4. The solar concentrator of claim 1 wherein the focal line is on an underside of the conduit.
 5. The solar concentrator of claim 1 further comprising a sun tracking mechanism, whereby as the sun moves through the sky during the day the sun tracking mechanism consistently points the concentrator towards the sun.
 6. The solar concentrator of claim 1 wherein each step has a common curvature.
 7. The solar concentrator of claim 1 wherein the apex of each step is offset vertically and horizontally from the reflector apex in a substantially circular pattern.
 8. The solar concentrator of claim 5 wherein the sun tracking mechanism is configured to adjust the position of the solar reflector so that the conduit remains at the focal line as the sun travels across the sky.
 9. A solar concentrator for heating a fluid, comprising: an extended solar reflector having a plurality of reflective concave steps, each reflective step having a common focal line; a conduit through which the fluid flows, the conduit positioned along the focal line of each step; whereby with the reflector positioned towards the sun, rays from the sun reflect from each step to concentrate along the focal line on the conduit to heat the fluid.
 10. The solar concentrator of claim 9 wherein the focal line is on an underside of the conduit.
 11. The solar concentrator of claim 9 wherein each step has a common curvature.
 12. The solar connector of claim 9 wherein each step has an apex offset vertically and horizontally from a reflector apex, and a bottommost step has an apex that is collinear with the reflector apex.
 13. The solar concentrator of claim 12 wherein the apex of each step is offset vertically and horizontally from the reflector apex in a substantially circular pattern.
 14. The solar concentrator of claim 9 further comprising a framework configured to support the reflector and conduit in a fixed relative relationship.
 15. The solar concentrator of claim 9 wherein the apexes of the steps define a generally parabolic shape.
 16. The solar concentrator of claim 9 wherein the conduit extends collinear with a long axis of the reflector.
 17. A method of heating a fluid, the method comprising: flowing the fluid through a conduit, providing an extended solar reflector having a plurality of reflective concave steps, each reflective step having a common focal line, the conduit being positioned along the focal line of each step; and heating the fluid by allowing rays from the sun to reflect from each step to concentrate along the focal line on the conduit.
 18. The method of claim 17 further comprising using a sun tracking mechanism to adjust the position of the solar reflector so that the conduit remains at the focal line as the sun travels across the sky.
 19. The method of claim 17 wherein the fluid comprises water. 